Grease pump



A. L. GRISE GREASE Puur Filed June 11, 1945 Dec, 24, 1946.

2 Sheets-Sheet l JE, 7gg@ Dec. 24, 1946.- A. L. GRISE 2,413,044

` GREASE PUE? Filed June 11, 1945 2 sheets-sheet 2 'Patented Dec. 24,1946 UNITED STATES :PATENT oFFlMcE Alfred L.Gris,GSI;Eri1sgliell:Mllass., assignor to Gilbert & Barker ManufacturingCompany, West Springfield, Mass., a. corporation of MassachusettsAppucauon June 11, 1945, serial No. 598,776

4 Claims. l

This invention relates to improvements in grease pumps and, moreparticularly, to grease pumps which may be used effectively with greasesof various consistencies from light to heavy and with greases at varioustemperatures.

The invention has for its principal object to provide an improved meansfor priming the' grease pump cylinder and insuring that a full charge isdelivered into the latter regardless of whether the grease is warm orcold or whether it is of light or heavy consistency.v

More particularly, the invention has for an object to provide a primingpump which is located below and is of larger capacity than the greasepumpand which is adapted to force some of the grease which it pumps intothe grease pump and to ley-pass the rest, the arrangement being suchthat the heavier the consistency of ,the grease, for less the amountthat is by-passed and vice versa.

'I'he invention has for a further object to provide for the delivery ofthe by-passed grease into an area surrounding, and closely adjacent to,the intake of the priming pump for the purpose of avoiding, or at leastsubstantially re`- ducing, the tendency to cavitation.

The invention will be disclosedwith reference to the accompanyingdrawimsin which,

Fig. 1 is a small scale exterior elevational view showing the manner ofmounting the grease pump in a grease dispensing apparatus;

Fig. 2 is a fragmentary view taken in the same direction as Fig. 1 butdrawn to a larger scale and showing the complete grease pump with itsinlet and outlet passages;

Fig. 3 is a sectional elevational view drawn to a still larger scale andshowing in full detail the grease pump proper, its associated primingFig. 5 is a sectional plan view taken on the i line 5-5 of Fig. 2;

Fig. 6 is a fragmentary cross sectional vview taken on the line 6--6 ofFig. 5.

Referring to these drawings; the grease pump is adapted to be applied toan original container o'f the grease to directly dispense the greasetherefrom. That is, the pump is suitably supported from or above thecontainer with its barrel extending downwardly into the same,terminating near the lower end thereof. As one example, a grease drum I,with its top cover removed, is mounted in cabinet 2 and the pump iscontained in a barrel t which is supported (Cl. 10S-203) 2 from the topwall' of the cabinet and extends downwardly into the drum, with theintake 1ocated close to the bottom 'of the drum. A follower plate 4 maybe used in the drum, when necessary, as it is with the heavier greases,such.

` follower resting on top of the grease and closely tting the drum andthe grease pump. In this case, and as best shown in Fig. 2, the pumpbarrel is supported from the lbase or lower head 5 of a iiuid pressuremotor of the reciprocating piston type, indicated as a whole at 6. headE has a.' central depending hub 1, tting into the upstanding hub of a,plate 9 which rests on the top wall of the grease cabinet 2 or suchplate may equally well rest on the cover of the grease drum. The hub 1has a shoulder whichrests upon the upper end face of hub 8 and supportsthe pump and its driving motor.

Any form of drive for the pump may be used. The driving motor 6,indicated herein, may for example be of the type shown in my copendingapplication Serial No; 598,775, led June 1l, 1945. The piston rod of themotor is shown at I0 and it extends through the head 5 and a' suitablestuiing box and downwardly into the pump barrel 3.

The upper end of the pump barrel S is xed,

las by the screw threads shown, to the lower end o1' 'an outlet pipe II.which in turn is xed, as by.v the screw threads shown, to an adapter I2,screw threaded into hub 1. Fixed, as by the screw threads shown, to thelower end of the grease pump barrel 3 is the upper end of the barrel I3of a priming pump. Threaded on the lower end of barrel I3 is a footvalve casing I4. The barrel I3 and casing Il are of the same diameterand of larger diameter than the barrel 3 or pipe II. A thin-walled tubeI5 of the same outside diameter as the barrel I3 and casing Il issecured to the upper end of the barrel I3 and extends upwardlyencompassing the barrel 3 and pipe II and terminating near hub 1. Thistube, with the barrel I3 and casing I4, afford a smooth cylindricalsurface along which the follower 4 can move up and down and which it cant with reasonable closeness.

The'grease pump cylinder, formed within barrel 3, is shown at I6.Reciprocable within cylinder I 6 is a piston comprising a body I1,having a long upwardly-extending hollow hub I8 and a depending hollowstud I9, on which is mounted the packing 20 and a washer 2|.l 'I'heupper end of the piston rod 22 of the priming pump is threaded onto thelower end of stud I9 and clamps the piston packing to its body.

The.

The motor piston rod I extends downwardly through pipe II, leaving anannularspace 28, and into the cylinder I8 with its lower end threadedinto the upper end of hub I8. Communication between the lower and theupper side of the grease pump piston may be had by way of an axialpassage 2Q, formed partly in the piston and partly in rod 22 andconnected by radial openings 25 in rod 22 to theipriming cylinder to bedescribed and by radial openings 26 in the hub I8 to the cylinder I5.Intermediate the ends of passage 24 is a .seat 2.1 on which rests a ballvalve 28, the upward movement of which is limited by a stop 29, secured,as by the screw threads shown, in the hollow hub I8.

The priming cylinder 30, formed within the barrel I3, is substantiallylarger in diameter than the cylinder I8. The upper end of cylinder- 30is in constant yand valveless communication with the lower end ofcylinder I8. In cylinder 30 is a piston comprising a body 3l, screwedonto the lower end of rod 22, and packing 32 mounted on the stud-likelower end 33 of the body and held with a washer tby a nut 85 to the body3|. There is an axial passage 36 leading from the lower end of stud 33upwardly into the body 3| and communicating with the cylinder 30 abovethe piston packing 32 by means of a plurality of radial passages 3l inthe piston body. A valve seat 88 is formed` in passage 38 intermediatethe ends thereof and resting on 'this seat is a ball valve 3Q, theupward movement of which is limited by a pin 40 xed at' its ends in body3i and spanning the upper end of passage 36.

The casing Id contains the inlet passage di which has a seat l2 adapted`to be engaged by a foot valve d3, having a plurality of radial guidewebs M, which slidably support it in the cylindrical bore d of casingld, The bore 45 communicates at all times with the lower end of primingcylinder 3i). Valve d3 is moved by gravity into closed position and islifted by suction on the upstroke of the priming piston.

Means are provided to carry away from the upper part of theprimingcylinder 3B any excess grease that cannot be taken up by the grease pumppiston. Such means includes a passage d6 formed in the barrel i3 andextending from its lower end upwardly to a point above the upper end ofthe stroke of the priming piston where it opens into the primingcylinder by means of aradial passage d1. In theupper end face of casingld is an annular groove 138 with which the lower end of passage dlcommunicates. In the casing I are formed a plurality of longitudinalpassages a9, the upper' ends of each communicating with groove d and thelower ends with the grease drum at points close to the inlet passageill. As shown, the lower end of casing Irl is made square to receive awrench and there are four passages 39 spaced ninety degrees apart andopening through the shoulders relieve excess pressure caused byexpansionof the-grease in that part of the priming cylinder below thepriming piston.

The outlet of the grease pump is by way of the annular passage 23 whichopens into a chamberl 51. The passage 56 has -a seat intermediate itsends and a springl pressed check valve 58 cooperates with said seat toprevent return iiow of the pumped grease.

Relief for excess pressure 'caused'by expansion of the grease in theoutlet passage 56' and the hose usually connected thereto, is providedfor by a spring-pressed relief` valve 59 (Fig. 5) which normally engagesa seat in a passage 80, formed in head 5 and leading from the passage56. A passage 6I connects passage E0 to a vertical passage 82 (Fig. 6)which extends downwardly to the base of hub 'I and opens into the greasedrum. Expansion of grease in the passage 23 and chamber 55' will openvalves 58 and 58 and' excess grease will escape by way of passages 6Iand 62.

Leakage past the piston rod I0 is likewise conveyed to the drum by apassage 63 which empties into the upper end of passage 62. YPassage 63extends through the sleeve-like wall 68 of the i stung box andcommunicates with an annular l 'H in the lower end of sleeve Sli ispressed upwardly by a spring 'I2 to compress the packing 'I6 againstgland 66 and through the latter to compress the packing 59. Leakage pastthe pist0n rod IIl will be collected in groove 5l flow through holes 66into groove 65 and from the latter by passages -63 and 62 into the upperend of the grease drum.

In operation; on an upstroke of the piston rod Iii, the grease pumppiston and priming pump piston are simultaneously raised from theirlowerr'nost positions shown to vthe positions indicated by dotted lines.The partial vacuum created below the priming piston in the primingcylinder causes foot valve i3 to open and grease is drawn into thepriming cylinder. At the same time, grease which has previously passedthrough the priming piston into the space above it is lifted upwardlyand forced into the lower end of the cylinder i6. So also, grease whichhas previously passed through the grease pump piston into the spaceabove it is raised upwardly and forced into outlet passage 23 to beeventually delivered through the latter and into chamber 55' and throughpassage 55 to the dispensing hose. On a succeeding downstroke, the footvalve closes and the piston valves 2% and 39 open so that the pistonspass through the grease, whereby charges of grease are transferred fromthe lower to the upper Sides of each piston.

As the pistons'rise, the priming piston forces grease into the lower endof the cylinder I6 and packs it, full. The area of the annular spacebetween the wall of cylinder 30 and rod 22 is several times (in thiscase about four times) that of the area between the wall of cylinder Itand rod 22. Accordingly, if the priming piston draws in a full charge ofgrease, only part of that charge can be forced into the grease pumpcylinder. The remainder must escape and it does so by way of the`passages 4T, t6, groove d8 and passages 49 into the grease drum. Withthe lighter greases. unless cold, the priming piston will draw in acharge more nearly equal to the amount that is theoreticaly possible andthe greater part of this charge will be by-passed back to the greasedrum. While the by-pass is of relatively small cross sectional area, itwill present much less resistance to light greases and warm greases thanto greases which are cold or which are of heavy consistency. As to coldgreases and heavy greases, much less than the theoretical charge of suchgreases will b taken in by the priming piston and less of the chargewill have to be by-passed. The small bypass presents so much resistanceto the flow of heavy or cold greases therethrough that grease will notby-pass unless and until the grease pump cylinder has been packed full.The arrangement vthus assures that the grease pump cylinder receives afull charge of any kind of grease that may be in the drum or othergrease container.

While the lay-passed grease may be ejected into the drum in variouslocations, it is preferred to do so in the manner herein disclosed. Thatis,

the ley-passed grease is `delivered downwardly is so directed as to fillany cavities that exist' and, in fact, so as to prevent or at leastsubstantially reduce the tendency to their formation by forcing theby-passed grease into thearea where the cavities are most likely toform.

The invention thus provides an all-purposel grease pump for use indispensing greases of arious consistencies and capable of emcient useirrespective of the consistency of the grease dispensed.

I claim: l

l. A pump, comprising, a pump cylinder, a priming cylinder having itsoutlet end connected to the inlet end of the pump cylinder, an inletvalve opening into the other end of the priming cylinder, interconnectedpistons one in each cylinder, each piston having a passageinterconnecting opposite sides thereof, a valve for each passage, eachvalve closing on the delivery stroke of its piston and opening on thereturn stroke to permit grease to be transferred fromthe suction to thedischarge side of its piston, the effective area of the priming cylinderbeing greater than the eective area of the pump cylinder, and a 6 lby-pass of relatively small area extending from the outlet part of thepriming cylinder in a direction parallel with the axis of the primingcylinder to the intake end thereof.

2. A pump, comprising, a pump cylinder, a priming cylinder having itsoutlet end connected to the inlet end of the pump cylinder, an inletvalve opening into the other end of the priming cylinder, interconnectedpistons one in each cylinder, each piston having a passageinterconnecting opposite sides thereof, a valve for each passage, eachvalve closing on the delivery stroke of .its piston and opening on thereturn stroke to permit grease to be transferred from the suction to thedischarge side of its piston, the eective area of the priming cylinderbeing greater than the effective area of the pump cylinder, and aby-pass of relatively small area extending from the outlet part of thepriming cylinder and delivering the by-passed grease inv a series ofjets surrounding the inlet of the priming cylinder.

3. A pump, comprising, a pump cylinder, a priming cylinder having itsoutlet end connected to the inlet end of the pump cylinder, an inletvalve opening into the other end of the priming cylinder, interconnectedpistons one in each cylinfder, each piston having a passageinterconnecting opposite sides thereof, a valve for each passage,eachvalve closing on the delivery stroke of its piston and opening onthe return stroke to permit grease to be transferred from the suction tothe discharge side of its piston, the effective area of the primingcylinder being greater than the effective area of the pump cylinder, anda by-pass of relatively small area connected to the priming cylinder ata point which at all times is on the discharge side of the primingpiston and extending to the area outside the priming cylinder andyadjacent the inlet end thereof.

4. A pump, comprising, a pump cylinder, a priming cylinder having itsoutlet end inv open and unrestricted communication with the inlet end'ofthe pump cylinder, an inlet valve opening into the other end of thepriming cylinder, interconnected pistons one in each cylinder, eachpiston having a passage interconnecting opposite sides thereof, a valvefor each passage, each valve closing on the delivery stroke of itspiston and opening on the return stroke to permit grease to betransferred from the suction to the discharge side of its piston, theeffective area of the priming cylinder being greater than the effectivearea of the pump cylinder, and a by-passl of relatively small areaconnectedI to the priming cylinder at a point which at all times is onthe discharge side of the priming piston and extending to the areaoutside the priming cylinder and adjacent the inlet end thereof.

ALFRED L. GRIS.

